Mercury boiler



May 30, 1939.

A. J. LARRr-:CQ 2,160,619

MERCURY BOILER Original Filed Feb. 27, 1935 Fig. l. I

' Fig. z.

giUA

\ Inventor:

Ah T l'l Ong J. Lorvecq,

Patented May 30, 1939 V2.160.619. 'MERCURY BoILER) nnthonylLarrecq; Schenectady, N. Y.,Sassignor 1to General Electric Company, ka corporationl of New York Application February 27, 1935,"seria1 No. 8,463

Renewed rOctober 26, 1938 Y f-4'c1aims (ci. 1era-facs) 1 'the header vI9 and .the separator k2I is effected The present'invention relates `to boilers,esp`e i cially mercury boilers, using as operating medium mercury or a mixture of mercury and otherksubstances, such as sodium, Vlithium or aluminum. More specically, the invention relates to that ele ment of boiler surface exposed tothe radiant heat of the furnace, namely, the wall screen. These wall screensusually are in the form of a plurality of tubes lining the wall of a furnace or combustion chamber. In'the type ,of'boilerheretofore used, mercuryliquid is conductedltoQthe lower ends of the wall screentubesby meansy off down-tubes disposed external the furnace, the term down-tubes -being used to indicate the downward ow of fluid as compared with the wall screen tubes or up-tubes through which the mercury flows upwardly.

The object Iof my invention is to provide an improved construction'and arrangement of vmer'- cury boilers having 'heating elements including down-tubes andup-tubes whereby the amount of mercury or operating medium necessary for op-erating a boiler is considerably reduced. Thislis accomplished vin accordance with my invention by exposing 'both the up-tubes and the downtubes to radiant heat and byithe Vprovision of liquid-vapor separating means connected to the ends of these tubes. With such an 'arrangement the down-tubes serve not only asa means for conducting liquid to the lower end of the up-tubes but also as a means for heating such liquid. Thus, in an arrangement accordingto my invention, both the down and the up-tubes constitute heat-absorbing surface. y

For a considerationl of what I believe to be novel and my invention, attention is directed to the following description and the claims appended thereto in combination with the accompanying drawing which forms a part of my'specication.

In the drawing, Fig. 1 is a diagrammatic i1- q lustration of amercury boiler embodying my invention; Fig. 2 is a sectional vi-ew along line 2 2 of Fig. 1; Fig. 3 is an enlarged detail View of a part of Fig. 1; Fig. 4 is a section along lines f--d of Fig. 3; and Fig. 5'is a modification according to my invention.

y The arrangement shown in Figs. 1 to 4 comprises a furnace having a wall Ii). The wall is lined by a plurality `of down-tubes I'I and uptubes I2. These tubes may bearranged in stag-V gered relation. Theupper ends of theftubesare connected to headers I3 and I4 including liquiddisplacing elements I3a andllla respectively. The headers I3 and I4 are connected by conduits I5 and I6 to a liquid-vapor separating device I'I having -a vapor discharge'conduit I8. The lower ends of the tubes I I and I2 are connected to lower headers I9 and 20 respectively which in turn are connected to a liquid-vapor separator 2i having' a discharge conduit 22. Theconnection between 'by a conduit; '23, the `connection between the vheader' 2B Vand the separator 2| being accomplished bya conduit 24 including a circulation pump 25. A conduit 24ais connected to the suction side of the pump 25 for conducting makeup mercury liquidto the system. f

During operation, liquid rmercury is conducted from` the upper 'separatori II 'through the discharge conduit t5 into the upper 'header I3, whence it flows through thedown-tubes I I into the lower header I9. The liquid is heatedrin the down-tubes I I and is-constrained to flow into the conduit 23 wherein its pressure is reduced'below the vapor pressure corresponding to the temperature of the liquid, prior to introduction into the lower separator 2|. The reduction of pressure causes a part of the liquid to evaporate, the vaporV being dischargedthroughv the conduit 22 and the liquid being discharged through the conduit 24 and forced by the pump 25 in this conduit through the lower header 20 into the up-tubes i2. The liquid is heated in the up-tubes i2 and discharged into the upper header I4, whence it'ows throughthe inlet conduit I6 into the separator I'I. The pressure of the liquid dis-charged by the v up-tubes is reduced below the vapor pressure corresponding to thetempefratureof thejliquid in the conduit I6, thus causing partial vaporization of the liquid prior to its introductionjinto theA conduit I8 and the separatorl'l. The vapor discharged through the liquid `is returnedl to the down-*tubes viaheader I3.' With this arrangement a oontinuousrcirculation of fluid through Y the series-connected down-tubes and up-tubes takes place. The arrangement is preferably such possible.v This `is a .distinct advantage of theboiler, another advantage'being, as stated before, that. the liquid is heated in both. down-'tubescand up-tubes. y K

As to the design of therlowervheaders'lt and V2l), it is to be noted that they areannular` in shape and have lateral projections 22 welded to openings and closed 4by an inwardly projecting cup-shaped member 21. This facilitates cleaning of the lower headers in that it permits easy access to the interior of lthe lower headers, access being obtained by removal of the cup-shaped ,members 21'. i l lteferrin'g''now more specicallyto the parti-cu; lar design of the liquid-vapor separating devices I1 and 2 I, as shown in Figs. 3 and 4, these-devices are alike in design.` The device I'l includes y-a double-Walled heat-insulated body 28 forming a lower' chamber or space 29 having a bottomcentrally connected to the inlet conduit I6. Secured to the bottom are a plurality of guide vanes 3G having a top plate 3|. The guide vanes 30 and the top plate 3| deflect fluid discharged from the conduit I6 vin tangential directionv towards-the cylindricalsurface 32 of the chamber 28. cross-sectional area 4between adjacent guide vanes 3G decreases Yin the direction of flow whereby `surface 32. This causes rotation of theluid and at the same time upward movement thereof. The inner surface of the body of fluid formed in the chamber 25 is indicated by a dash-dotted line 33. YThis fluid is primarily liquid because the centrifugal forces induced by the -tangential motion'of the uid tend to separate the liquid and the vapor, th-e liquid being thrown outward'by the action of the centrifugal force, and the vapor escaping to the central portion of the chamber 29. The body of liquidin the chamber was it reaches the upper end thereof has considerable velocity. This velocity is partly converted into pressure by means of guide vanes 34 secured to the vupper end of the chamber 2S. The wall portion 35 surrounding the guide vanes 34 forms a scroll for receiving liquid discharged from the passages formed by said guide vanes 34. The guide vanes 34, Vas' just pointed out, convert the velocity energy of the liquid into pressure energy and thereby increase the liquid pressure to force the liquid into the discharge conduit i5. conduit l5 has two branches 35 and 3l connected to diametrically opposite portions of the scroll. Thus, the liquid-vapor separator utilizes a part of the kinetic energy of the mixture discharged therein to recirculate the liquid andin this respect supports th-eV action ofV the circulating pump 25. [in annular plate 38 is secured to the 4upper ends of the guide vanes 34. This plate 38 forms a support for studs 3S which, together with an annular plate or ring 40, carry a cylindrical member lil. The latter Vforms a passage through which vapor is discharged intoan upper or vapor space e2 oi the separator. The vapor space 42 has a serrated wall'd3. The iluid is discharged towards this wall by means' of deflectors. 44 con- Vcentrically disposed about the cylindrical member il and'havinglower ends sured to the ring 40 and upper ends secured to a disk 45. The provision of the serrated wall 43 'and of the means for discharging the fluid towards Athis wall serves to remove or separate liquid particles contained in the vapor. The liquid particles flow downwardly along the serrated wall 43 through the annular space defined between the plate members 38 and d into the lower chamber 29 and the vapor is discharged through the conduit I8.

The modification shown in Fig.`5 comprises a furnace wall 5fand a porcupine type boiler having a drum l5| and porcupine tubes 52. The drum 5l is connected to a vapor discharge conduit 5|a The Y The discharge I.

a conduit 54 and a header 55. The lower end of the down-tube` 53 is connected through a separator and aV pump (not shown) similar to the arrangement of Fig. 1 to an up-tube 56 which discharges through a header 5l and a conduit 58 into the drum 5|. The headers 55 and 51 in this arrangement correspond to the headers I3 and I4 of Fig. 1. In the present instance they are formed by a single tubular member having a separating wall 59. `'Ihe conduit 58 for discharging iluid from the header 5l to the drum 5| also includes a strainer 60 having a bypass 6| with a valve 62. The arrangement of Fig. 5 is an application of my invention shown in Fig. 1 to a porcupine type boiler whereby the boiler drum 5| acts as a liquid vapor separator.

Having described themethod of operation of my invention, together `with the apparatus which I now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of `the United States, is:

1. In a boiler, an up-tube exposed to heat, means including a pump connected to the lower end of the up-tube for forcing liquid to be heated therethrough, a first liquid-vapor separating device connected to the upper end of the up-tube for separating the mixture of liquid Vand vapor discharged from the up-tube, a down-tube exposed to heat having an upper end connected to the liquid-vapor separating device for receiving liquid therefrom, means including a second liquid-vapor separating device connected to the lower end of the down-tube for separating the mixture of liquid and vapor discharged therefrom, said pump having an inlet conduit connected to the second liquid-vapor separating device,`and means for discharging vapor from both devices, theV rst liquidvapor separating device being located at a level above that of the tubes.

2. In a boiler, the combination of 11p-tubes and down-tubes located adjacent each other and Y uniformly exposed to heat, means for forcing liquid through the up-tubes, a vapor-separating device connected to the upper ends of all of the tubes, a second vapor-separating device connected to the lower ends of the down-tubes, and

means for discharging vapor frein both devices. L

3. In aboiler, the combination of a plurality vapor separatingV means connected to the upper and lower ends respectively of the tubes. v

4. In a boiler, the combination of up-tubes and down-tubes having upper and lower ends located at substantially the same levels respectively,

means for circulating operating fluid through the tubes, said means including a liquid-vapor separating device connected to the upper ends of the Vtubes and located above said upper ends, and

another liquid vapor-separating device connected to rand located near the lower ends of the tubes, l

separatevapor discharge conduits connected te both liquid vapor-separating devices and means for heating both tubes.

ANTHONY J. LARRECQ. 

